This article is kindly written for us by Dr Chris Davies, who is the Head of Technical Research & Innovation at Belron Technical, based in the UK. We asked Chris to explain the value and benefit we get from being part of a global company concerning technology and insights related to future trends. Here’s what Chris has to say…
Seat belts and airbags provide secondary safety benefits for the occupants of a vehicle, meaning that the technology is there to try to minimise the injuries suffered in the event of an accident, and these have no benefits for other road users. Advanced Driver Assistance Systems (ADAS), on the other hand are primary safety technologies that are designed to prevent the accident from happening and, if it can’t be avoided, to at least reduce the severity of any impact. More modern and advanced ADAS systems are not only designed to protect the occupants of a vehicle, but also other vulnerable road users, such as pedestrians and cyclists. The commonly fitted ADAS safety systems built into vehicles today are Forward Collision Warning (FCW), Autonomous Emergency Braking (AEB), Lane Departure Warning (LDW) and Lane Keeping Assist (LKA). FCW and AEB are intended to prevent or avoid frontal collisions (and in the case of AEB to also reduce the energy of impact due to a collision), and LDW and LKA systems are designed to prevent unintentional departure from the road lane.
Originally the main driver of ADAS adoption by vehicle manufacturers in Europe was the New Car Assessment Program, known as EuroNCAP, which was very successful in accelerating technology implementation, however this has now been augmented with the introduction of legislation. The EU has introduced laws which mandate that new to market type approved models must be fitted with certain ADAS systems as standard from 2022.
From 2024 onwards, all new cars sold in the EU must also have these ADAS system fitted as standard, meaning that over time the complete car parc of those countries will be equipped with primary safety technology, like AEB or LKA.
While penetration rates of ADAS systems in various countries in the EU are still growing, on our estimates, potentially reaching 50% in some territories in the next couple of years, the safety benefits of the technology are becoming evident from several global studies of collision data. A 2018 study undertaken by BMW in collaboration with Impact Research LLC showed that 2014 model year vehicles fitted with FCW and LDW were 13% less likely to crash than those without these systems, and this number increased to 34% amongst the 2017 model year, highlighting the advancement in the efficacy of the technology. A November 2022 study by the NHTSA PARTS (Partnership for Analytics Research in Traffic Safety) group estimated a 49% reduction in front to rear crashes when the approaching (frontal impact) vehicle was fitted with both FCW and AEB, and a 53% reduction in associated injuries. When the approaching vehicle is only fitted with the simpler FCW warning system, as opposed to both FCW and AEB where there is active braking, the reduction in crash frequency is 16% and 19% for associated injury. The difference between crash occurrence when the vehicle is fitted with warning (FCW) and active braking (AEB) compared to warning alone, agrees with the earlier BMW study where newer vehicles exhibited better performance as the installed technology became more complex.
To deliver the required functionality of these ADAS systems the vehicle needs to be fitted with sensors that provide information on the surrounding environment. The two sensors that are most used are radar and cameras because they are relatively low cost and have specific advantages for delivering the required ADAS functionality. Radar functions in all weather conditions, is very good at detecting the presence of objects and has a long sensing range so is good for functionality at a wide variety of driving speeds. However, radar can’t tell what an object is, or see colour, meaning that for many ADAS functions a camera is needed to provide the needed input for the safety system software. Whereas simple FCW or AEB systems could function adequately with just a radar module, for today’s more complicated systems that also need to detect pedestrians and cyclists, a camera is essential to determine what is in front of the vehicle. Also, only a camera can determine the lines on a road or recognise speed limit signs meaning that they are essential for the operation of ADAS functions like LDW, LKA and Traffic Sign Recognition (TSR).
To correctly deliver the functionality of the ADAS technology the safety system software uses the output of the camera to determine where the vehicle is in the road and what, and how close an object may be in front. If the camera is moved, such as is the case if the windscreen is replaced, the image that the software sees will change, meaning that it may mistakenly think that the vehicle is in a different location in the roadway or closer or further from an object in front. This is dangerous, particularly if the vehicle is fitted with active safety systems like AEB or LKA, and could result in incorrect activation (or not in some cases) of the steering or brakes, potentially resulting in an impact if the driver has not reacted. The recalibration process reteaches the ADAS safety system software where the new camera position is, so that it now knows where the vehicle is correctly located relative to the roadway or an object, like a pedestrian, in front. Recognising that the ADAS system camera requires a recalibration if the sensor is moved, most vehicle manufacturers stipulate the requirement for this to be undertaken when a windscreen is replaced in their published repair methods.
A badly recalibrated vehicle can also be unsafe in certain circumstances, as the ADAS software may wrongly determine its position in the roadway or relative to an object in front, and this may result in the incorrect activation (or not) of the braking or steering systems. In such circumstances, even though the ADAS software believes it is recalibrated, the system incorrectly learns (calculates) the position of the camera image relative to the driving axis of the vehicle. Vehicle manufacturers knowing how critical the recalibration process is for the correct and safe functionality of the ADAS systems, specify in their repair methods the requirements for a flat and even floor and for good, uniform lighting. This is why recalibrating at the roadside, where the floor could be uneven and where the lighting is unpredictable, is not recommended and could result in the incorrect functionality of the ADAS systems.
The windscreen is a great platform for mounting technology on or in the glass, as it offers a view of the road ahead and provides protection from the weather and dust and dirt. With the introduction of ADAS systems and their associated sensors, the brackets on the glass have become bigger and more complex. This has not only impacted the cost of the part, but also affects other areas of the supply chain, like transportation, handling and storage, as packing densities have decreased due to the bigger and wider brackets. As well as cameras, there other sensors commonly attached to the glass, like rain and light sensors, lidar and even radar modules (for example with some Volvo models), which also may require separate recalibration or resetting after a windscreen replacement, having an impact on the tools required, correct processes and time needed to complete the job. Head Up Display (HUD) and the more complex Augmented Reality (AR) versions, where location or directional information is projected onto the screen as well as the usual speed or fuel level data, are being introduced onto premium models more and more, and these add further complexity to the glass replacement process in requiring optics adjustment and camera recalibration, as well as needing a replacement part with the correct plastic interlayer to remove potential issues with double images. Matrix headlights are another technology that is slowly entering the market, and these are controlled in many cases from a camera behind the windscreen. While at the moment these systems don’t require a recalibration after a glass replacement, we expect this to change over time, particularly as more of these complex vehicles systems interact through what’s called sensor fusion. With vehicles becoming more connected to infrastructure and other road users (V2X) in future we assume that there will be more antennae, for example for RFID, 5g and GPS, embedded into the windscreen and this will add further cost and complexity to both the supply chain and to the operational business.
The growing trend in complexity is driving challenges for the supply chain, the need for constant tool and process innovation and a skills and job time impact for operations. As more technology is getting added to a windscreen the number of vehicle models that have some repair restrictions on certain zones on the glass is growing. Chip repair in the glass area in front of a camera or HUD is not recommended and as the fitment frequency for these technologies grow the ability to deliver this service will decrease.